How big is the universe?

Added: 2026-05-19

[00:00:00]If you're a space fan, then you'll want to hear this cosmic secret. The universe is way bigger than you think. Let's break it all down one light-year at a time. The observable universe isn't the whole universe. It's more like our cosmic neighborhood. Think of it as a gigantic bubble stretching 46.5 billion light-years from Earth in every direction. Why just that size?

[00:00:23]Because light, our cosmic messenger, takes time to travel.

[00:00:27]The universe is 13.8 billion years old, so you might guess we could only see 13.8 billion light-years out.

[00:00:35]But, here's the twist. The universe has been expanding since the Big Bang, stretching that bubble much farther. So, what's inside? Over 100 billion galaxies each filled with stars, planets, and who knows what else. We haven't detected everything in our bubble yet. Our tech isn't quite there. But, every time we build a better telescope, we peer a little farther into our cosmic backyard.

[00:00:57]Space is big, but our curiosity even bigger.